1. Field of the Invention
This invention relates to a container which serves the purpose of dispensing products, generally of cosmetic or pharmaceutical type in the form of a solidified stick-shaped fluid, such as deodorants or lipsticks, or of a viscous fluid, such as a creme, a gel or the like.
The container is of the type comprising a driving member having a central threaded opening, such as a stick-holder or a pressing piston endowed with a rotational and translation motion controlled by an axial threaded rod, following a mutual rotation of two bodies which are external to the container and reciprocally rotatable.
2. The Prior Art.
Containers of such general kind are already well known in the prior art, some representative examples of the same being lipstick containers and stick-shaped deodorant containers which are available on the market, as well as containers disclosed in my preceding Italian patent application no. 47711A88 which also comprises creme dispensing devices.
Dispensing containers for a viscous fluid or a stick-shaped solidified product, wherein said stick is supported by a driving member endowed with a rotatory-translation motion according to the prior art are disclosed in my preceding patent application mentioned above, and: an outer tubular body having a circular section inner surface, a bottom end closed by a closure bottom and a threaded rod integral with said closure bottom and which projects along the axis of the external body towards its top portion; an inner tubular body which is coaxial with said external body and has an outer surface in sliding contact with the inner surface of the external body, and an opening corresponding to its top end, said internal and external bodies being constrained by engagement means which hinder reciprocal motion in the axial direction, so that a rotational relative motion can be performed about their common longitudinal axis, and said internal body protruding above the top part of the external body; said driving member being movable according to a rotational and translation motion following the reciprocal rotation of the external and the internal bodies, as it is engaged through a threaded engagement on a central opening with a threading in said rod, and as it is slidable with its external wall along said inner surface of the internal body.
The rod which is integral with the bottom of the external body is considered a drawback because it is hard to mold, as said rod is molded within a glass-shaped tubular body and is provided with a number of undercuts due to the reduced pitch threading.
In my patent Italian application no. 47711A88 mentioned above now U.S. Pat. No. 4,984,718, an example has been illustrated in FIG. 10 of a rod which is provided at the basis of the plate, and is molded separately from the outer body bottom and is made successively integral through snap axial engagement of openings in the plate itself which engages with respective small projecting portions starting from the bottom surface of the outer body.
The shining material which is commonly employed for aesthetic purposes to make the outer body is not very elastic so that it is not very suitable for being molded so as to bear inner undercuts in the inner bottom of the external body.
It is to be taken into account that an easy molding operation for such component bodies of the container is of fundamental importance both from the practical and the commercial viewpoint.
Other conventional containers which are available on the market for stick-shaped products include a holder which is threadedly engaged with a rod which is integral with the controlling body and is slidable along the inside of the internal body, which rod is normally provided with one or more guiding grooves in its outer surface, which engage with respective guiding ribs on the inner surface of the internal body, so that said rod is constrained to move in the axial direction in order to avoid the rotation of the driving body that drives the rod integrally into rotation.
The presence of ribs is often prejudicial to the outer aspect of the stick-shaped product, and such ribs cannot be employed for containing a fluid material and least of all for preserving volatile or degradable materials contained in the product.